1. Field of the Invention
The present invention relates to an external operating device for a molded case circuit breaker and, more particularly, to an actuator mechanism having assembly notches in a slider assembly and a mounting plate having attachment points located to the side of the circuit breaker operating handle, adapted to be coupled to a circuit breaker operating handle, for moving the operating handle to an open position or, alternatively, to a closed position, which may be controlled from a handle that is external to the circuit breaker enclosure.
2. Description of the Prior Art
Molded case circuit breakers are generally used to provide overcorrect protection for various types of electrical equipment. However, in some applications, it is desirable to have an operating device for the circuit breaker that is external to the circuit beaker enclosure. Such external operators make it easier to operate the circuit breakers. Such a remote control system is also useful for molded case switches.
In such applications, external operators have been provided that are adapted to be mechanically coupled to the operating handle of the circuit breaker or molded case switch. The external operator is, typically, a lever or handle attached to a cable. The cable is coupled to an actuator assembly mounted on the face of the circuit breaker. The actuator assembly includes a mounting plate assembly and a slider assembly. The slider assembly includes a rigid member having a formed cutout sized to fit about the operating handle of the circuit breaker. The slider assembly further includes a bent tab coupled to the cable When the external operating handle is actuated, the cable acts on the slider assembly which moves the circuit breaker operating handle between the open and closed position. The prior art actuator assemblies suffer from at least two disadvantages. First, one type of actuator assembly has three components, a slider assembly, a first mounting plate and a second mounting plate. It would be more cost effective to reduce the number of components. Additionally, the two-part mounting brackets were attached by two fasteners on each bracket. Should the fasteners on either one of the mounting brackets become unattached to the circuit breaker, the entire device may be rendered inoperable. Some actuator assemblies have only one mounting plate assembly, and thus only two parts. The slider assembly tab is inserted into the bracket and the slider is fished through the slot until the end opposite the tab can be inserted into the bracket. A portion of the slider assembly is wider than one of the slots, thus, the slider assembly is captured in the slots by the bent tab and the wide portion. Manufacturing costs and procedure could be simplified if the slider assembly were more easily installable.
A second disadvantage of the prior art actuator assemblies is that the mounting plate assemblies typically placed the bracket fastener openings within, or near, the generally straight path of travel of the circuit breaker operating handle. That is, for a circuit breaker mounted with the operating handle moving between an xe2x80x9cupxe2x80x9d position and a xe2x80x9cdownxe2x80x9d position, the mounting plate assembly attachment openings would be located above and below the operating handle. In certain models of circuit breakers, a trip unit is disposed in the area xe2x80x9cbelowxe2x80x9d the actuating handle. Use of the prior art mounting plate assembly would interfere with adjustment controls on the trip unit.
Therefore, there is a need for an actuator assembly that can be more easily assembled in the field.
There is further need for an actuator assembly, to be used with circuit breakers having a trip unit with controls disposed adjacent to a circuit breaker operating handle, with a mounting plate that does not block access to the trip unit controls.
These needs and other needs are satisfied by the present invention which provides an actuator assembly having a slider assembly having a wide portion and a narrow portion, and a mounting plate assembly having an open slot sized to cooperate with the narrow portion to allow the slider assembly to be inserted into the mounting plate assembly. The slider assembly is a rigid, generally planar member. The planar member includes at least one lateral notch disposed between the wide portion and the narrow portion. At the location of the notch, the planar member has a reduced width. The wide portion includes a formed cutout. The slider assembly also includes a tab that is generally perpendicular to the planar member. The mounting plate assembly includes two slots, a first slot sized to correspond to the slider assembly narrow portion, and a second slot sized to correspond to the slider assembly wide portion. The first slot has a partially open top that is sized to correspond to reduced width of the planar member at the location of the notch.
To construct the actuator assembly, the slider assembly is inserted into the mounting plate assembly by passing the reduced width portion of the rigid planar member through the opening in the partially open first slot. The wide portion of the slider assembly is then aligned with the second slot. The narrow portion is then slid through the first slot until the wide portion enters the second slot. Once assembled, the narrow portion is constrained by the first slot and the wide portion is constrained by the second slot. Thus, the actuator assembly may be constructed out of only two components and be assembled in the field.
Additionally, the mounting plate assembly is structured with mounting openings that are attached to the faceplate on either side of the circuit breaker operating handle. That is, spaced to the sides of the path of travel of the operating handle. As such, the mounting plate assembly does not extend to the area occupied by the trip unit. Therefore, the mounting plate assembly does not block access to the trip unit controls or prevent the opening of a flip lid over the trip unit controls.